This invention relates to protected documents.
Modern copiers, and especially color xerography copiers, have greatly expanded the potential for document counterfeiting. An art of protected documents has developed as a result. This art is rooted in such engraved image practices as byzantine, embellished document backgrounds. This art has progressed to such developments as dot patterns including non-copyable small dots for background and copyable large dots for warning indicia.
Flaws in current protected documents included background densities which are unacceptably high, failure to function with poorly maintained or intentionally altered copiers, poor hiding of warning indicia, limits on compatible inks and density ranges and inflexibility in background color and pattern selection.